PORTLAND, Ore. (AP) — A young Somali-American man convicted of plotting to bomb a 2010 Christmas tree-lighting ceremony in Portland’s town square has written an apology letter in advance of his sentencing and says he renounces his former beliefs.

In the letter filed Friday by his lawyers in federal court, Mohamed Mohamud offers to speak to young Muslims “to help keep them away from the path of extremism” and tells U.S. District Judge Garr King he turned to books to help himself “walk a better path.” His reading list ranges from “The Grapes of Wrath” to President Barack Obama’s “The Audacity of Hope” to “A Zombie Apocalypse.”

Mohamud was arrested Nov. 26, 2010, after pressing a button on a cellphone that he believed would detonate a 1,800-pound diesel-and-fertilizer bomb near thousands of people at the annual holiday gathering.

The bomb was a fake supplied by undercover FBI agents posing as al-Qaida recruiters.

On Jan. 31, jurors rejected Mohamud’s entrapment defense and found him guilty of attempting to detonate a weapon of mass destruction.

A sentencing memo filed Friday by federal prosecutors agreed with U.S. probation officials who calculated that Mohamud should be sentenced to life in prison. However, the prosecutors did note that there are factors in the 22-year-old former Oregon State University student’s case that would allow the judge to be more lenient. In that event, prosecutors asked for a sentence of 40 years.

Mohamud’s defense team suggested 10 years.

The judge is expected to hear arguments regarding the sentence and possibly hear from Mohamud at a hearing Sept. 6, but the date may change.

The Oregonian and KGW-TV carried reports on the court filings.

The 107-page defense memo included the apology letter and reports from two government psychiatrists who describe Mohamud as a low risk of “future dangerousness.”

“Mohamed’s life is worth saving: he will prove himself worthy of any mercy the court can provide to temper what he knows will be a significant prison sentence,” his lawyers wrote. “The family’s indescribable suffering at the loss of the eldest son should be mitigated to the extent possible.”

Mohamud wrote that reflecting on his conduct “fills me with horror.”

“My heart is filled with remorse, shame, sorrow, pain and misery every time I think about my actions on that day,” he said.

And he added, “I am sorry and I regret it, not because of jail time but because my heart is truly in shock.”

Mohamud has been in jail since his arrest.

“I turned to books to expand my mind and explore the words of others and see where I could grow as a whole and let broader ideas into my mind,” he wrote.

The reading list filed by the defense included nearly 150 books, among them: “Animal Farm,” ”Pride and Prejudice,” ”The Quran” and “Zen and the Art of Motorcycle Maintenance.”

In conclusion, Mohamud told the judge, “I give you my word to make the best use of my incarceration, to make myself a better person and to help my fellow inmates to do so as well.”